Looking at the code in 2.5.0, the qemu_chr_fe_write method would see EAGAIN too, because the tcp_chr_accept() method would always set the newly connected client to non-blocking mode. So thre's no obvious change in behaviour between 2.5 and 2.6 wrt to blocking sockets.
Looking at the code in 2.5.0, the qemu_chr_fe_write method would see EAGAIN too, because the tcp_chr_accept() method would always set the newly connected client to non-blocking mode. So thre's no obvious change in behaviour between 2.5 and 2.6 wrt to blocking sockets.